The Latin word canicŭla came to our language as canicula . This is what the hottest time of the year is called.
During the dog days, therefore, the heat is felt more strongly. This period can last between four and seven weeks, depending on the region. It should be noted that the dog days are also known by the following names: dog days, dog days, dog days .
It is estimated that the dog days begin several days after the summer solstice , which takes place on December 21 in the case of the southern hemisphere and June 21 in the northern hemisphere . It should be noted that, on the solstice , the Sun is located in one of the tropics.
The increase in heat in the heat wave is associated with the way in which the Earth 's axis tilts with respect to the Sun. This means that, when the highest temperatures are reached in one hemisphere, the opposite occurs in the other hemisphere and record the lowest temperatures.
The heatwave occurs when the area in question receives a greater amount of solar radiation . Once summer begins, the oceans warm up and a few weeks later the highest temperatures are reached.
For astronomy , the dog days are the time in which the star Sirius , which is the brightest star in the Can constellation, is located next to the Sun. This situation, in ancient times, coincided with the hottest phase in the northern hemisphere.
In some countries , finally, a period of drought that occurs during the rainy season is called dog days.
Regarding the etymology of the word dog days , its history is quite peculiar and interesting. It turns out that in its origin we can find nothing less than the Latin term canis , which translates as "dog" in our language. Of course, at first glance it does not seem to have a great relationship with "the hottest time of the year."
But its name has nothing to do with man's best friend, but with the aforementioned star of Sirius, which is also known by the nickname "the Scorching" and belongs to the constellation Canis maior , which in Spanish we call Can Elderly. In the northern hemisphere, during some summer nights this star is the brightest.
This property was wrongly interpreted by our distant ancestors, who believed that the heat of Sirius merged with that of the Sun and this caused the increase in temperature and the decrease in rainfall on our planet throughout the month in which the so-called canicular rigors .
Some stories tell of people in Central America who, in the past, decided to temporarily stop their planting tasks during these weeks because the decrease in humidity was counterproductive. They also associated the dog days with the position of Canis major, and hence they used this name for the phenomenon.
In addition to the damage to agriculture, the heat wave was also associated with certain diseases that proliferate with heat, such as the plague , which can affect humans and animals and is caused by a bacteria called Yersinia pestis .
Nowadays this coincidence no longer occurs, but the word heatwave continues to be used. Precisely, today Sirius is once again noticeable in the sky during the first days of September, in the morning, and this is due to the phenomenon called precession movement of the Earth's axis or precession of the equinoxes , that is, the variation of its axis. , which takes place every 25,767 years.